This invention relates to unsaturated polyester compositions containing a polymer of a conjugated diene.
It is known in the art to produce unsaturated polyester compositions containing rubber. However, it has been found that such compositions tend to exhibit separation when combined with a reinforcing agent or filler, thus impairing the physical properties, particularly impact strength.
Liquid or semi-solid rubbers which can simply be mixed with polyesters to produce thermosetting compositions are also well known and a broad spectrum of low molecular weight liquid or semi-solid rubbers are suggested in the art for use in such compositions. However, low molecular weight rubber compositions tend to give very poor surface finish in systems containing a reinforcing agent or filler.